Bromochlorodifluoromethane (Halon 1211)

Older portable fire extinguishers (especially aviation) and some fixed suppression systems; it can form acidic, toxic fumes when heated in fires [1][2].

Breathing the gas during a discharge or leak, during testing/maintenance, or when re‑entering a recently protected space—especially if ventilation is poor [1][2].

Short-term exposure can cause dizziness, confusion, poor coordination, fainting, and dangerous heart rhythm changes; very high levels can displace oxygen. Fire breakdown products add further risk. It also depletes ozone and contributes to climate change [1][2][3].

Firefighters; aircraft crew/passengers; extinguisher and suppression‑system workers; people with heart or lung conditions; anyone in confined spaces [1][2].

Avoid unnecessary discharges; evacuate and ventilate after use; follow labels and workplace procedures; consider EPA‑approved alternatives; during fires, use SCBA and verify air quality before re‑entry [2][3].